Apparatus for the manufacture of synthetic threads



Oct. 25, 1966 J. w. HEIJNIS APPARATUS FOR THE MANUFACTURE OF SYNTHETIC THREADS Filed Feb. 26, 1964 FIGI a; 4 WWW l hfijliui If 26 Ti t? C, :Z'.' Z1

INVENTOR JAMES WATT IJ SBRAND HEIJNIS ATTORNE United States Patent 5 Claims. c1. 1s s Thi invention relates to an improved apparatus for the manufacture of synthetic threads by the melt spinning method, and more particularly to an improved apparatus advantageously useful in melt spinning synthetic threads of relatively low denier and/or essentially uniform denier.

Melt spinning apparatus adapted with a cooling chamber for the freshly spun filaments are known. In such devices the filaments are spun directly into the cooling chamber and therein contacted by a flow of air introduced into the chamber in a direction perpendicular to the spinning direction. It is desired to adjust the rate of air flow through a bundle of the spun filaments to be constant throughout the filament pattern. Variations in the cooling air flow are detrimental in that such a condition cause final, cooled threads obtained from a given bundle to differ significantly from one another in denier and diameter.

Spinning apparatus having cooling chambers heretofore available are arranged such that the spinning chamber surrounds the spinneret(s) with the front wall thereof and two side walls thereof which are perpendicular to said front wall extending parallel to the direction of spinning. The front wall of such spinning chambers is provided over its entire surface with openings which connect with an air-supply system.

With such known apparatus of the above-described type, there are the problems that the flow of air in the cooling chamber is unsatisfactory and i not the same along the entire length of the bundle of filaments, thus causing the threads of the bundle, particularly in the case of apparatus having more than one spinneret, tend to become entangled. To overcome this thread entanglement problem, it has been proposed, with known apparatus provided with a spinning nozzle having more than one group of spinning orifices, to locate partitions between the successive groups of spinning orifices. But when adopting such a proposal, it has been found that the problem of variations in the rate of air flow throughout the filament bundle still remains. Experiments with these prior art apparatus having such entanglement-precluding partitions have shown that with a rectangular bundle of filaments the rate of air flow in the middle zone thereof, at equilibrium conditions, is practically constant, but that in the zones to the side of the bundle the rate of air flow is from approximately lower to approximately higher than the air flow rate in the middle zone. The undesirable result of this is that undesirably there are variations in the pattern in air flow rate throughout the filament bundle which cause unsatisfactory, relatively large differences in denier and diameter in the threads obtained.

Additionally, with such spinning apparatus, having a plurality of groups of spinning orifices, it is often a necessity to remove the spinning nozzle for cleaning, repair, and/ or replacement. In an effort to facilitate such operations, it has been proposed to design the apparatus in a manner permitting the entire cooling chamber to be moved sideways so that it is entirely outside the spinning zone and facilitate the removal and/ or exchange of the spinning assembly from below. The displacement of the cooling chamber as a whole however, calls for a construction which is not advantageous to such an expedient, particularly where space may be at a premium.

Accordingly, it is the primary object of the present invention to provide an improved filament spinning apparatus having a spun filament cooling chamber which is essentially free of the disadvantages attendant similar apparatus heretofore available. 1

It is another object of the present invention to provide an improved filament spinning apparatus having a spun filament cooling chamber advantageously characterized by an ability to simply and efliciently, without problems of thread entanglement, provide spun filaments of the desired characteristics.

It i an additional object of the present invention to provide :an improve-d filament spinning apparatus having a spun filament cooling chamber which is adapted to provide an essentially constant rate of flow of the cooling medium throughout the pattern of the freshly spun filament bundle.

A further object of the present invention is to provide an improved filament spinning apparatus having a spun lament cooling chamber advantageously adapted for removal and/ or exchange of the spinning nozzle without the need of effecting a shifting of the entire cooling chamber.

It is a particular object of the present invention to provide an improved filament spinning apparatus having a spun filament cooling chamber which is simple in construction and provides spun filaments having a significantly improved uniformity of denier and diameter as compared to those produced by similar, previously available apparatus.

These and other objects and advantages of the present invention will be apparent from the following detailed description thereof.

Briefly and in summary, the present invention provides a filament spinning apparatus consisting of at least one spinneret provided with a plurality of orifices for spinning a bundle of filaments and a cooling chamber positioned to at least partially surround said filament bundle being spun by said spinneret. The cooling chamber has a front wall and two side walls with said front wall extending essentially parallel to the path of travel of filaments in said filament bundle and being provided over its entire surface with openings for passage of air through same. The side walls are positioned essentially parallel to said filament path of travel and are perpendicular to said front wall. Means are also provided for supplying air communicating with said front wall of said cooling chamber, and at least two resistance members are provided on opposite sides of said filament bundle with each resistance member extending in a direction parallel to the filament path of travel and are adapted to be fixedly positioned within said cooling cahrnbe-r on a line between said'side walls and said filament bundle. The distance from the path of travel of the filament in said filament bundle nearest thereto is at most five times the smallest distance between adjacent orifices in said spinneret.

In describing the invention more in detail and particularly to various preferred embodiments of the spinning apparatus of the invention, each resistance member is so positioned during normal spinning that the distance therefrom to said sides of the corresponding group of spinning orifices in the spinneret is about one to two times the smallest distance between the successive spinning orifices of the spinneret.

The particular embodiments of the resistance members may vary. The resistance members preferably function as auxiliary side walls and are characterized by an area which is at least as great as, and preferably greater than,

that of the area defined by said intermediately lying filament bundle in a plane parallel to the side walls of said cooling chamber. The resistance members may be of a continuous .or discontinuous surface and, in embodiments wherein the surface of the resistance member is discontinuous, e.g., perforated, the openings therein are sufiiciently small so as not to substantially disrupt the flow pattern of air passing traverse to said member. Preferably, however, the air-contacting surface defined by the resistance member is continuous and, in such embodiments, the surfaces of the resistance member partitions preferably extend in the direction of air flow over a smaller distance than do the side walls of the cooling chamber. The invention contemplates, however, embodiments wherein the side walls of the cooling chamber are positioned such that they also serve as the resistance members.

The invention also contemplates an embodiment wherein the resistance elements define areas smaller than that of the filament bundle in a plane parallel to said cooling chamber side Walls. Particularly in a cooling chamber provided with a single spinneret, the resistance members suitably may consist of one or more steel Wires having approximately the same dimensions as the synthetic threads being formed in the spinning operation. Screens formed of such wires are also contemplated.

Preferably, the resistance members are movable from the spinning position to some spinning-in position farther removed from the adjacent spinner-ct. By the use of such a design, the spinning-in operation does not give rise to dificulties and the cooling chamber advantageously may be adapted to different spinnerets and conditions. A further preferred construction is obtained if all of the resistance memebrs consist of continuous partitions which are alidably but sealingly attached to the front wall, which is generally in the form of a conventional screen pack, of the cooling chamber.

The resistance members act to reduce the differences between the rate of air flow at the sides and in the middle of the filament bundle to a value which allows filaments of substantially uniform denier and diameter to be obtained. Advantageously, the apparatus according to the invention makes it possible to spin uniform threads having a denier lower than 1.5, namely 1.2 and lower, which previously has not been possible when using previously known cooling chambers.

The invention contemplates embodiments of the spinning apparatus provided with a plurality of spinnerets, each spinneret being adapted with a pair of resistance members. In certain embodiments of the invention having more than one spinneret wherein the position of one or several of the resistance members is fixed, a single esistance member may serve as the member for two spinnerets lying on each side thereof. As employed herein, the term spinneret is intended to refer'to a spinning nozzle having a single group of closely lying orifices or the area of a spinning nozzle provided with a plurality of distinct groups of closely lying orifices in which is located one of said distinct groups.

With embodiments of the apparatus of the invention in which the outer circumference of the group of spinning orifices in the spinneret defines a rectangle whose long sides are parallel to the front wall of the cooling chamber, it is preferred that the resistance member partitions extend substantially parallel to the short sides of the rectangle formed by the group of spinning orifices. A particularly favorable result is obtained with such embodiments if the orifices in the spinneret are so relatively positioned that on any straight line extending over the spinneret parallel to the direction of air flow through the filament bundle only one spinning orifice is located.

According to the invention, each spinneret having a group of spinning orifices may be located between two separate resistance members and the members may be moved pairwise and in a direction approximately transsmall.

Verse to the direction of air flow, towards one another into a spinning position or moved away from one another into a spinning-in positon. Thus, as stated above, the spinning-in operation does not give rise to problems and the cooling chamber has flexibility in terms of usage with spinnerets of difiering design. In the case of a spinning nozzle provided with several distinct groups of spinning orifices, or spinnerets, the presence of'two movable resistance member partitions between two adjacent groups of spinning orifices ensures that the distance between said distinct groups of spinning orifices is not particularly While in the spinning-in position, the two movable outer resistance member partitions of the assembly may be placed practically against the adjacent side Walls of the cooling chamber. In this position, the distance from such two movable outer patri-tions to the sides of the corresponding group(s) of spinning orifices preferably is at least ten times the distance between the successive spinning orifices in a group.

The invention contemplates embodiments wherein the spinning nozzle provides a round or a rectangular bundle of filaments. Spinning means are preferred, however, which spin a rectangular bundle of filaments.

Having been broadly described, the invention 'will be further described with reference to the accompanying dnawings of which:

FIGURE 1 is a schematic plan view in cross section of a spinning apparatus of the invention having a cooling (FIGURE 2 chamber for one spinneret;

FIGURE 2 is a schematic view on an enlarged scale of the group of spinning orifices in the spinneret shown in FIGURE 1;

FIGURE 3 is a schematic view in cross section of an apparatus of the invention having a cooling chamber for three spinnerets; and V FIGURE 4 is a partial schematic view of a different embodiment of the apparatus of the invention having a cooling chamber for one spinneret assembly.

In FIGURE 1 the numeral 1 designates a front wall of the cooling chamber consisting of a screen pack. Positioned perpendicular to front wall 1 are side walls 2 and 3. Between side walls 2 and 3 and parallel to front wall 1 is a schematically shown rectangular bundle of filaments 4. Filament bundle 4 is formed by spinneret 4' located above same and represented by dotted lines. Spinneret 4' is provided with a group of spinning orifices 11 Parallel to side walls 2 and adjacent each of the short sides of rectangular filament bundle 4, are two resistance members in the form of partitions 5 and 6, respectively, which members are sealingly attached to front wall 1. Behind, and communicating with, front wall 1 is air supplymeans 39. The direction of flow of air from supply means 30 for cooling filament bundle 4 is indicated by arrow A. Spinning-in positions for partitions S and 6 are drawn as dotted lines. In such positions they are practically against sidewalls 2 and 3, respectively. Partitions 5 and 6 may be moved over a distance B to spinning positions which are indicated by the solid lines. The displacement over distance B of partitions 5 and 6 may be effected with the aid of a set of guides 7 and 8, respectively, by which members 5 and 6 are supported, said guides preferably being located on the outside of the cooling chamber.

Partitions 5 and 6 are displaced by means of a system of coupled rods 9 and 10, respectively, which rods are provided with means not shown for fixing same in the desired position. a

In the spinning position (solid lines) the distance from partitions 5 and 6 to be correspondingly adjacent sides of filament bundle 4 is at most five times, preferably approximately once to twice, the smallest distance between the successive spinning orifices 11.

FIGURE 2 is a view on a larger scale of the substantially rectangular pattern of spinning orifices of spinneret 4' showing spinning orifices 11. Each row of orifices 11 parallel to the long side of the rectangular pattern contains about 72 spinning orifices 11 which are spaced apart at intervals of about 4.5 millimeters. The overall pattern contains 7 of these rows, which rows are spaced apart at intervals of about 5 millimeters. With resistance members 5 and 6 in the spinning position (solid lines, FIGURE 1), the distance from each of partitions 5 and 6 to the correspondingly adjacent sides of the pattern of orifices preferably is one to twice the distance of 4.5 millimeters, i.e., 4.5 to 9 millimeters. The direction of flow of the cooling air again is indicated by arrows A. On any straight line extending on the spinneret parallel to the direction of air flow only one of the spinning orifices 11 is located, as appears from a set of flow lines 12 shown in the left hand part of FIGURE 2.

In FIGURE 3, like numerals refer to like elements shown in FIGURE 1. In FIGURE 3 the cooling chamher is adapted for cooling three schematically shown rectangular bundles of filaments 13, 14 and 15 formed by spinnerets 13', 14 and 15, respectively, positioned above and shown as dotted lines. The direction of flow of the cooling air is again indicated by arrows A. Each of the filament bundles 13, 14 and 15 are located between two separate pairs of resistance member partitions 16-17, 18-19, and 20-21, respectively, which partitions may be moved (by means not shown) over the distances B transverse to the direction of flow of the cooling air from spinning positions (solid lines) to spinning-in positions (broken lines).

In FIGURE 4 again like numerals refer to like elements as shown in FIGURE 1. In FIGURE 4 the cooling chamber is adapted for cooling a single schematically shown substantially rectangular bundle of filaments 4. With this embodiment there are no partitions adjacent to side walls 2 and 3, but side walls 2 and 3 themselves serve as resistance members and preferably may be displaced over a distance B from the spinning position (solid lines) to the spinning-in position (broken lines) by means not shown.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of this invention.

What is claimed is:

1. A filament spinning apparatus which comprises at least one spinneret provided with a plurality of orifices for spinning a bundle of filaments, a cooling chamber positioned to at least partially surround said filament bundle being spun by said spinneret, said cooling chamber having a front wall and two side walls, said front wall extending essentially parallel to the path of travel of filaments in said filament bundle and being provided over its entire surface with openings for passage of air through same, said side walls being positioned essentially parallel to said filament path of travel and being essentially perpendicular to said front wall, means for supplying air communicating with said front wall of said cooling chamber, and at least two resistance members on opposite sides of said filament bundle adapted for movement relative thereto, each resistance member extending in a direction parallel to said filament path of travel and being adapted to be fixedly positioned within said cooling chamber on a line between said side Walls and said filament bundle at a distance from the path of travel of the filament in said filament bundle nearest thereto of at most five times the smallest distance between adjacent orifices in said spinneret.

2. The apparatus according to claim 1 wherein the distance between each of said resistance members and the paths of travel of said filaments in said filament bundle nearest thereto is from about one to two times the smallest distance between adjacent orifices in said spinneret.

3. The apparatus according to claim 1 wherein said resistance members are partitions defining continuous surfaces and wherein said partitions extend to engage said front wall of said cooling chamber and said front wall of said cooling chamber is in the form of a screen pack.

4. The apparatus according to claim 3 wherein said orifices in said spinneret are positioned in a pattern to provide a bundle of spun filaments having a cross-section approximating a rectangle and said spinneret is positioned so that the long sides of said rectangle are essentially parallel to said front wall of said cooling chamber, whereby said partitions extend substantially parallel to the short sides of said rectangle.

5. The apparatus according to claim 1 wherein a plurality of spinnerets is present and a resistance member is positioned on each side of a group of spinnerets and are adapted for movement in a direction approximately transverse to the direction of the flow of air forced through said cooling member by said air supply means.

References Cited by the Examiner UNITED STATES PATENTS 2,940,122 6/1960 Collart 188 2,947,029 8/1960 Balsker 188 3,067,459 11/1962 Brand 1S8 3,070,839 1/1963 Thompson 18-8 OTHER REFERENCES Ser. No. 362,260, Egger (A.P.C.), published April WILLIAM J. STEPHENSON, Primary Examiner. 

1. A FILAMENT SPINNING APPARATUS WHICH COMPRISES AT LEAST ONE SPINNERET PROVIDED WITH A PLURALITY OF ORIFICES FOR SPINNING A BUNDLE OF FILAMENTS, A COOLING CHAMBER POSITIONED TO AT LEAST PARTIALLY SURROUNDING SAID FILAMENT BUNDLE BEING SPUN BY SAID SPINNERET, SAID COOLING CHAMBER HAVING A FRONT WALL AND TWO SIDE WALLS, SAID FRONT WALL EXTENDING ESSENTIALLY PARLLEL TO THE PATH OF TRAVEL OF FILAMENTS IN SAID FILAMENT BUNDLE AND BEING PROVIDED OVER ITS ENTIRE SURFACE WITH OPENINGS FOR PASSAGE OF AIR THROUGH SAME, SAID SIDE WALLS BEING POSITIONED ESSENTIALLY PARALLEL TO SAID FILAMENT PATH OF TRAVEL AND BEING ESSENTIALLY PERPENDICULAR TO SAID FRONT WALL, MEANS FOR SUPPLYING AIR COMMUNICATING WITH SAID FRONT WALL OF SAID COOLING CHAMBER, AND AT LEAST TWO RESISTANCE MEMBERS ON OPPOSITE SIDES OF SAID FILAMENT BUNDLE ADAPTED FOR MOVEMENT RELATIVE THERETO, EACH RESISTANCE MEMBER EXTENDING N A DIRECTION PARALLEL TO SAID FILAMENT PATH OF TRAVEL AND BEING ADAPTED TO BE FIXEDLY POSITIONED WITHIN SAID COOLING CHAMBER ON A LINE BETWEEN SAID SIDE WALLS AND SAID FILAMENT BUNDLE AT A DISTANCE FROM THE PATH OF TRAVEL OF THE FILAMENT IN SAID FILAMENT BUNDLE NEAREST THERETO OF AT MOST FIVE TIMES THE SMALLEST DISTANCE BETWEEN ADJACENT ORIFICES IN SAID SPINNERET. 